Canada may screen all passengers leaving Toronto's main airport as it quarantines hundreds of people in their homes to combat a mysterious respiratory disease and quell growing public unease, health officials said yesterday.

Air Canada has one daily roundtrip flight to Bermuda from Toronto.

Canadian medical officials said they hoped their new procedures to combat severe acute respiratory syndrome - a troubling pneumonia-like infection - will work.

They said the condition of people diagnosed with the disease, which is known as SARS, was either stable or improving. There are now 28 probable SARS cases in Ontario, with another ten suspect cases and 21 under investigation.

The disease has killed more than 50 people worldwide, including three in Canada.

The World Health Organisation (WHO) yesterday urged the screening of travellers from areas worst hit by a killer pneumonia, including Toronto.

Bermuda Airport general manager James Howes said he had alerted Immigration and key airport staff but how passengers from Toronto would be handled was a matter for Immigration.

He said: "I am not placed to make decision of that nature. They make decisions about the fitness to admit someone into Bermuda."

Home Affairs Minister Terry Lister could not be reached for comment.